Electromagnetic circuit controller



Oct. 2, 1945. c. T. EVANS ELECTROMAGNETIC CIRCUIT CONTROLLER Filed July12, 1943 max I 42/ 5. 81mm @g wvwk a;

I i fifm ua x ing in both time and Patented Oct. '2, 1945 itELECTROMAGNETIC cmourr CONTROLLER Clarence '1. Evans, Wauwatosa, Wis,assignor to Milwaukee, .Wis., a cor- Cutle'r-Hammer, Inc poratlon ofDelawar Application July 12, 1943, Serial No. 494,279

A (or. 115415) 4 Claims.

This invention relates to electromagnetic cir-- I cult controllers andis particularly applicable to those for use aboard ships or in otherlocations where severe shocks are likely to be encountered and wherelarge switches are required.

i As will be understood, the demand for switches to meet test for severeshocks extends to large switches as well as tosmallswitches oi the relaytype of which several forms have been designed and developed to possessinherently the required characteristics to meet test or theaforementioned character. Also as'will be understood, redesign of acomplete line of switches of dinerent sizes isboth-very costly and timeconsuming.

e test to be met does not require that the of more: than momentary breakand also against possibility" of circuit making when the switch issupposed to be open, and the present invention has among-its objectsto'affordthe needed characteristics to a switch not inherentlypossessing the same, and by way of. simple additions savcost as comparedwith redesign. p x

Another object is to provide means to thus render shock proof switchessubjected tocontrol in various ways including the so-called 3 wirecontrol afl'ording' low voltage protection.

Various other objects and adva'ntages of the invention will hereinafterappear.

According to the present invention it is proposed to aflord the neededcharacteristics to a switch not inherently possessing suchcharacteristics through'coordinating therewith one or another oftherelativelyinexpensive relays which have been designedto possessinherently the switch be restrained against.m0mentary break circuitbutdoes require protection against characteristics required to meettests of the afore mentioned character..

The accompanyingdrawing illustrates schematically and diagrammaticallyone embodiment or the present invention which will now be describedyitbeing understood that the embodiment illustrated is susceptible ofvarious modiilcations without departing from the'scope of the appendedclaims. I

In the drawing,

Figure 1 is a more or less schematic view of the switch and associatedrelay, and

Figs. 2 and 3 are diagrammatic views of diiferent control circuits forthe switch and relay.

Referring to Fig. l, the switch schematically illustrated thereincomprises stationary contacts 1 and 2 carried by a suitable fixedsupport 3 and cooperating movable contacts 4 and 5 carried by thearmature 6 of a suitable electromagnet. The electromagnet as showncomprises a winding 7 carried by a magnetic frame 8 having a portion 8constituting a supporting core for the winding 1. The armature 6 has anangular extension I 0 which may be assumed to coact with part of themagnet frame 8 to limit outward movement of the armature 6 under theforce of gravity to disengage contacts 4 and 5 from contacts I and 2. Aswill be understood, winding 1 is energizable to effect attraction ofarmature 6 for engagement of contacts 4 and 5 with contacts I and 2 andas will become apparent the switch might assume various forms other thanthat illustrated.

The associated relay selected for illustration (see Fig. l) is of a formnow in use and disclosed in a pending application assigned to theassignee hereof, Serial No. 493,81l,.filed July 8, 1943, by C. W. Kuhn.This relay briefly described comprisesan electromagnet having astationarily mounted winding l2, and axially aligned magnet plungers l3and I4 therefor biased apart by springs I5 and I6, respectively, andadapted to be drawn together electromagnetically upon energization ofwinding l2. The plungers l3 and H carry respectively at their outer endsacross bars I! and I8 in turn respectively carrying contacts l9 and 20.These contacts are separated by the plungers I3 and it when moved apartand are engaged by attraction of the plungers upon energization ofwinding l2, the contacts being thus afforded rectilinear movements forengaging and disengaging. While in practice the contacts l9 and 20preferably are additionally afforded limited rocking play against thebias of suitable springs, thus being yielding when brought intoengagement, this detail has been omitted from the schematic showing. Thefloating structures comprising the plungers and the contacts carriedthereby are preferably balanced and are interconnected to prevent at alltimes independent movements thereof and to subject them to counteractionone by another under shocks. This interconnecting means is shown ascomprising a disk 2i having a fixed axis 22 and I arms 23 and 24 whichrespectively link the cross bars I! and I8 of the two plungers to thedisk 2| vat diametrically opposed points on the disk equally spaced fromits axis.

Also in practice the biased movements of the plungers are limited bysuitable means not illustrated in the schematic showing. Such a relay,as aforeindicated, has

been found to meet satisfactorily severe shock test regardless ofdirection of shock.

The aforedescribed relay is associated with the switch both mechanicallyand electrically. Considering the mechanical association the relay isused to control a latch to lock the switch in open position. This latchis shown schematically as comprising a double ended lever 25 having afixed pivot 28, the upper end of the lever being adapted to underlie theextension It of the armature of the switch when the switch is open, and

the lower end of the lever having a suitable connection 21 with therelay through a link II. The arrangement is such that when the switchand relay are deenergized the relay plungers under their bias throw thelever 25 into interlocking relation with the switch to block closurethereof, whereas energization of the relay winding effects movement ofthe plungers to swing the lever 2| chanical influence of the relaythrough the latch lever 25. To make the switch when closed sufficientlyshock-proof to meet the aforementioned test which permits, of momentarybreak of circuit by the switch the relay is used to afford a maintainingcircuit for the switch winding I so long as closure of the switch isdesired. This the relay will accomplish because it is inherentlyshock-proof and with the switch supplied uninterruptedly with current ifsaid switch opens under shock it will be quickly reclosed with at themost mere momentary interruption of circuit. Different ways in which therelay maybe so utilized to protect the switch winding againstinterruption or supply of current to winding 1 are depicted in Figs. 2and 3.

Referring to Fig. 2 which shows one form of so-called 3-wire control,the windings l and I! are arranged to be supplied from a circuit 33-under the control of a normally closed push button switch and a normallyopen push button switch 36. Supply of current to the winding 1 isdependent upon prior response of the relay to engage its contacts l9 and20. When the push button switch 3! is closed it connects the relaywinding I2 across the circuit 3lfl through the normally closed pushbutton switch II, whereupon said relay responds to connect winding Iacross said circuit through the normally closed push button switch 3!.Thus energization of switch winding I is not dependent upon continuedclosure of the normally open push button switch It and relay contactsl9'and 20 when eneaged shunt the push button switch it, wherefore therelay winding I! will remainenergized upon release of push button switch38. This provides for continued energization of winding "I so long asthe relay winding i2 remains energized. and as aforestated energizationof the latter will be continuous regardless of shock, assuming continuednormal voltage. Should abnormally low voltage occur the relay would, ofcourse. release. deenergizing the switch winding 1, insuring againstreenergization thereof pending restoration of normal voltage and pendingreclosure of push button switch 36.

Referring toFig. 3, the same also shows a socalled 3-wire control forthe switch winding I comprising a normally closed push button switch I!and normally open push button switch it like those of m. 2, but in thisinstance the relay is provided in addition to contacts I! and 2| withother contacts 31 and fl, to afford separate maintaining circuits forthe two windings. More speciflcally, contacts I! and." control thecircuit of the switch winding I just as in Fig. 2, whereas the relaycontacts 81 and 38 establish for the relay winding I! a maintainingcircuit shunting the push button switch II. This arrangement is inpractice usually preferred to the arrangement shown in Pig. 2, and theadditional relay contests may comprise another set of contacts likecontacts II and 2| or may comprise certain of the auxiliary contactswith which the relay of the type shown is commonly provided, preferablyof that type disclosed in the aforementioned Kuhn application.

It will, of course, be understood that other forms of shock-proof relaymay be substituted for the particular form shown for illustration.

What I claim as new and desire to secure by Letters Patent is:

1. The combination with an electromagnetic switch, likely under severeshock, when said switch is either energized or deenergized, to effectcircuit commutation, of an electromagnetic relay of greater stabilityunder likeshock, and means coordinating said relay with said switchelectrically and mechanicalhr to enhance the shock proof characteristicsof said switch when energized or deenergized.

2. The combination with an electromagnetic switch likely when energizedor deenergized to eflect circuit commutation under sever shock, ofcontrol mean therefor comprising an electro- 0 magnetic relay havinggreater stability under like shock, said means locking said switch in afixed position when said switch and said relay are deenergized and saidmeans when said'relay is energized maintaining said'switch energizedwhereby any change in position of said switch when said relay isenergized will be only momen- 3. In combination, an electroresponsiveswitch, an electroresponsive relay having under severe shock, whenenergized or deenergized, greater stability than said switch, circuitconnections rendering said relay and said switch responsiveprogressively with said switch under the control of said relay forinitial and continued energization of said switch, and locking meansunder the control of said relay to restrain said switch in a ilxedposition under severe shock when said switch is deenergized.

4. In combination, an electroresponsive switch,

an electroresponsive relay having under severe shock, when energized ordeenergized, greater under the control of said relay to'restrain saidswitch in a fixed position under severe shock when said switch isdeenergized.

CLARENCE T. EVANS.

